• Title/Summary/Keyword: NMR study

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Theory of NMR Spectoscopy and Its Application in Geoenvironmental Sciences (NMR 분광법의 원리와 지구환경과학에의 응용)

  • 김영규
    • The Journal of the Petrological Society of Korea
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    • v.10 no.3
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    • pp.233-245
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    • 2001
  • With the advent of super-conducting magnet, NMR spectroscopy becomes a very important tool in geology as well as in chemistry. $^{29}Si$ and $^{27}Al$ which are the main components of minerals and contain structural informations, are useful major targets for the NMR study in geology, but some other elements including alkali cations such as $^{23}Na$ are also one of them. NMR can be applied to many different fields. For example, it can be applied to study smaller range of structure (in molecular level) than XRD and TEM. NMR provides us with structural informations such as order-disorder in Al and Si distribution, oxygen coordination number, and distribution of other cations. Another important information that we can obtain from NMR is not only the static structural informations, but also the molecular dynamics. This dynamic informations of molecules also enable us to figure out the frequency of molecular motion and activation energy. Structure of amorphous minerals and chemistry and structure of natural organic materials are also studied by NMR.

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On the Structure and the Extent of Disorder in Non-crystalline Silicates at High Pressure: 2 Dimensional Solid-state NMR Study (2차원 고상 핵자기 공명기를 이용한 비정질 규산염의 고압구조 및 무질서도에 대하여)

  • Lee Sung Keun
    • Journal of the Mineralogical Society of Korea
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    • v.18 no.1
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    • pp.45-52
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    • 2005
  • The recent development and advances in 2 dimensional solid-state NMR, particularly, triple quantum (3Q) MAS NMR yield much improved resolution compared with conventional 1 dimensional MAS NMR, allowing us to study the distributions of cations and anions in the non-crystalline silicate glasses and melts. Here, we present the recent progress made by 3QMAS NMR spectra of silicate glasses quenched from melts at pressures up to 10 GPa in a multi-anvil apparatus, revealing previously unknown details of structures of covalent oxide glasses and melts at high pressure.

Characterization of the Catalytic Heteropoly Compounds using Solid-state NMR

  • Kim, Y;Lee, W
    • Journal of the Korean Magnetic Resonance Society
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    • v.1 no.1
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    • pp.45-58
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    • 1997
  • Heteropoly compounds, H3PMo12O40, CsxH3-xPMo12O40, and vanadium containing heteropoly compound were characterized by Solid-state broad line 1H MAS NMR, 31P MAS NMR, and High Speed MAS 51V NMR spectroscopy of quadrupolar nuclei. The effects of calcination, dehydration, and the number of protons on the structure of heteropoly compounds were studied. The results of this study demonstrate that these Solid-state NMR techniques are very useful tools to study heteropoly compounds.

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Practical Guide to NMR-based Metabolomics - I : Introduction and Experiments

  • Jung, Young-Sang
    • Journal of the Korean Magnetic Resonance Society
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    • v.21 no.3
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    • pp.96-101
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    • 2017
  • Metabolomics is one of latest '-omics', which is to analyze metabolome in cells, tissues and biofluids and to study metabolisms. It has become increasingly popular since 1990. The first goal of metabolomics is to analyze metabolites in a technical aspect. The major two analytical platforms in metabolomics are NMR spectroscopy and mass spectrometry (MS). MS is superior to NMR for detecting many more metabolites. That is one of the most important factors in metabolomics. However, NMR also has several advantages over MS. In this review, I firstly introduced metabolomics by comparing NMR-based metabolomics and MS-based metabolomics. Second, I explored technical issues on sample preparation and NMR experiments for metabolite identification and quantification.

Application of the Projection Operator Technique to the Study of NMR Line Shape and Free Induction Decay Curve (NMR 吸收線 모양과 誘導磁氣自由減衰曲線 硏究에의 投影演算子法의 應用)

  • Lee Jo W.;Sung Nak Jun
    • Journal of the Korean Chemical Society
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    • v.21 no.5
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    • pp.362-371
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    • 1977
  • In this paper application of the projection operator technique to the study of NMR absorption line shape and free induction decay curve is explored. It is found that the projection operator technique can provide a convenient means for deriving a set of hierarchy equations which may serve as a good starting point for theoretical calculation of the absorption line and free induction decay function by successive approximation or by an appropriate decoupling approximation. A brief review of linear response theory of NMR line shape and the relation between the absorption line shape and free induction decay function are also described.

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Analytical Study for an Acrylic Coating (아크릴 코팅의 성분 분석 연구)

  • Kim, Seog-Jun
    • Analytical Science and Technology
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    • v.17 no.2
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    • pp.98-107
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    • 2004
  • In this study, $^1H$ NMR spectroscopy and HPLC were used to identify the type and quantity of each component in an acrylic coating materials applied for an automotive part. By the $^1H$ NMR analysis, it was found that this acrylic coating contained about 88.40 wt% of poly methyl methacrylate (PMMA), 7.05 wt% of methyl methacrylate (MMA), and 2.36 wt% of allyl methacrylate. Polymer additives such as a benzotriazole light stabilizer (Hisorb 328), an oxanilide light stabilizer, butylated hydroxy toluene (BHT), and dimethyl phthalate (DMP) were also identified and measured quantitatively from the $^1H$ NMR spectra. However, only two light stabilizers were identified by reverse phase (RP) HPLC analysis using Bondapak C18 column, methanol mobile phase, and a PDA (Photodiode array) detector. The contents of two light stabilizers in the acrylic coating were measured by a quantitative analysis through UV-Vis spectroscopy and compared with the NMR data. The analytical informations from $^1H$ NMR spetra were better than those from HPLC-PDA plot.

Solid-state NMR Study on Membrane Protein Structure in Biological Condition

  • Kang, Su-Jin;Lee, Bong-Jin
    • Journal of the Korean Magnetic Resonance Society
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    • v.16 no.2
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    • pp.103-110
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    • 2012
  • Membrane proteins play a essential role in the biological systems and it is not easy to handle a membrane protein for its structural study. Solid-state NMR (ssNMR) can be a good tool to investigate the structures and dynamics of membrane proteins. In ssNMR, Magic Angle Spinning (MAS) and Cross Polarization (CP) can be utilized to reduce the line-broadening, leading to high resolution and sensitivity in the spectrum. ssNMR, if combined with other spectroscopic methods, can provide us a enough knowledge on structures and dynamics of membrane proteins in biological condition.

Single-Crystal $^{27}Al$ NMR Study of Corundum α-$Al_2O_3$

  • 우애자
    • Bulletin of the Korean Chemical Society
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    • v.20 no.10
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    • pp.1205-1208
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    • 1999
  • 27Al NMR chemical shielding, quadrupolar coupling, and dipolar coupling interactions for corundum (α-Al2O3) are determined from the single-crystal 27 Al NMR spectra according to the rotation about three orthogonal axis. 27 Al NMR parameters obtained in this work with high accuracy are as follows: δiso = 7.4(4) ppm, QCC = 2.30(4) MHz, h = 0.08(3), and R = 2.0(3) kHz. This work appears to be the first NMR measurement of an aluminum-aluminum dipolar coupling interaction in α-Al2O3 crystals.

A Study on the 300MHz NMR Transceiver (300MHz급 NMR Transceiver 설계 및 제작)

  • Park, Yang-Ha;Jin, Seung-Oh;Won, Jin-Im;Huh, Young
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.3210-3212
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    • 2000
  • We designed and manufactured 300MHz NMR RF Transceiver. NMR system is composed of NMR Spectrometer, Superconductive Magnet and Pulse Programmer, GUI. NMR RF Transceiver is composed of transmitter, receiver, frequency synthesizer. T/R switch, main power amp., RF coil. To phase modulation, transmitter is composed of mixer, splitter and combiner et al. To weak signal detection, receiver is composed of pre-amp., filter, mixer et al. Each module is manufactured PCB. And installed NMR system to detect chemical component of specimen. In result, we can get the information of specimen.

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